Basic categories for city and settlement sizes. Based on the work of Sload, roerich, Yeti and Infragris. Adapted to PO's needs.

Size guidelines

Tier I: Major cities. Between 50 and 80 interiors. Most quests, services and factions headquarters can be found here. Ruled by a King, a Clan Mother and high-ranking administration members. Note that city size should correspond to economical and environmental factors: trade cities like Riverhold and Senchal should be large and varied, while places like Orcrest and Alabaster should edge to the 60 int limit.
Examples: Senchal, Torval, Corinthe, Orcrest, Dune, Riverhold, Alabaster, Rimmen.

Tier II: Large towns. Between 30 and 50 interiors. They feature modest guildhalls, a variety of shops and a decent selection of quests. Usually ruled by a Head of Clan and a Clan Mother with the presence of an imperial administrator. Should also have a good reason for being there: trade, mining, logging, farming, fishing...

Tier III: General towns. Between 40 and 15 interiors. Market-towns, large villages, other sizable settlements. Feature an incomplete set of services, very limited faction options or quests. Governed by a Head of Clan and a Clan Mother.

Tier IV: Villages, between 15 and 5 interiors. Feature a single tavern or inn, very limited in other services. Governed by a Head of Clan or a Clan Mother. Usually no faction quest-givers.

Tier V: Single homesteads, farms, inns, camps, etc. 5-1 interiors. Virtually no services, very limited number of NPCs. Might be ruled by a local citizen or a Clan Mother, though often these should not even require such detail.